Migrate Shenandoah to OpenJDK infrastructure

[Roman Kennke]

Hello,

As you probably already know, Shenandoah has been accepted as OpenJDK
project.

Starting today, we will use OpenJDK infrastructure for hosting
Shenandoah development. This means:

1.
Use http://mail.openjdk.java.net/mailman/listinfo/shenandoah-dev as
mailing list for discussions and development.

2.
Use https://wiki.openjdk.java.net/display/shenandoah/Main as wiki.

3. Code repositories are http://hg.openjdk.java.net/shenandoah

You will notice that there's a JDK9 *and* JDK8 branch in there. Yes, we
will be maintaining both from now on.

I imported the existing Shenandoah code to those repositories as one
big changeset. The Mercurial history will remain on Icedtea servers,
should anybody be interested in it.

If you're interested in Shenandoah, please try it out and let us know
how it goes.

Cheers,
Roman